\input pstfig
\hskip 2cm
$
\setcoorunit{4}{1}
\psset{yunit=0.4\psxunit}
\psset{xunit=1.2\psxunit}
\drawaxes{-2.5}{2.6}{-5}{5.3}
\uput[-50](0,0){\scriptstyle O}
\markxlabel{-2}{-2\pi}{-2em}
\markxlabel{-1}{-\pi}{-1.5em}
\markxlabel{1}{\vphantom{2}\pi}{-1em}
\markxlabel{2}{2\pi}{-1.5em}
\psplot{-1.92}{-1.08}{1/sin(x*\pinum)}
\psplot{-0.92}{-0.08}{1/sin(x*\pinum)}
\psplot{0.08}{0.92}{1/sin(x*\pinum)}
\psplot{1.08}{1.92}{1/sin(x*\pinum)}
\dashline\thinline
\psline(-2,4.4)(-2,-4.4)
\psline(-1,4.4)(-1,-4.4)
\psline( 0,4.4)( 0,-4.4)
\psline( 1,4.4)( 1,-4.4)
\psline( 2,4.4)( 2,-4.4)
$
\bye
